I need a fully-functional e-commerce frontend built with React. The core feature in scope right now is a smooth, intuitive shopping-cart flow that works flawlessly on desktop and mobile. Everything should be written in modern React (hooks, functional components, and clean state management); feel free to suggest Redux Toolkit, Context API, or another clear approach if it keeps the codebase maintainable. To make expectations crystal-clear, here’s what I need handed over: • Responsive product listing and detail views styled with clean, reusable components • Add-to-cart, update quantity, and remove-item interactions, persisting state across page refreshes • A dedicated cart page or slide-out drawer with subtotal calculation and graceful empty-state handling • Integration hooks ready to plug into my existing API endpoints (fetch products, sync cart, etc.) • Well-commented code, a concise README, and any build scripts needed to run the project locally Everything should ship ready to yarn install, yarn start, and look pixel-perfect. Let me know if you plan to add TypeScript or a UI kit like MUI or Tailwind—those are optional, but I’m open if they accelerate development while keeping the bundle lean.